结合泛型使用,不然就只能写成for(Object o : T)。
缺点是没有下标,如下面代码
public class ForeachTest { public static void main(String[] args) { String[] s = {"kobe" , "tracy" , "tim" , "shark"}; StringBuffer sb = new StringBuffer(); for (int i =0 ; i < s.length ; i++){ if (i == s.length-1){ sb.append(s[i]); }else { sb.append(s[i]); sb.append(","); } } System.out.println(sb); } }
kobe,tracy,tim,shark
如果用foreach来做
public class ForeachTest { public static void main(String[] args) { String[] s = {"kobe" , "tracy" , "tim" , "shark"}; StringBuffer sb = new StringBuffer(); for (String str : s){ sb.append(str); sb.append(","); //kobe,tracy,tim,shark, 多了一个逗号 } //所以去截掉一部分 System.out.println(sb.substring(0 , sb.length()-1)); //kobe,tracy,tim,shark } }